1. Field of the Invention
This invention relates to a method of effecting a transverse stretch or elongation of a fibrous or film-like material and to an apparatus for carrying this method into practice.
2. Prior Art
There have been proposed many methods and apparatus for stretching a fibrous or film material monoaxially in the transverse direction. A typical example known in the art is a tentering system designed to grip the longitudinal edges or selvages of an elongate sheet material and stretch this material transversely while being heated. Such conventional devices are rather costly and space-consuming. Furthermore, they suffer from the drawback that the magnification of stretch of a given material, particularly where this material is non-fibrous such as a plastic film, is limited by the rupture which would take place at areas of the material where longitudinal stresses are created during progressive transverse stretching.